As we have already mentioned, in contrast to other similar one-factor models like the time-dependent Ornstein-Uhlenbeck, Hull-White, CIR and CEV models which have been considered in [1]}, [2]}, [3]}, the solution of the pricing problem for the BK model is not known in closed formSome approaches for doing that are discussed in [4]}.. Therefore, we propose an approximation that gives rise to a semi-analytical solution for the barrier Call option price. This approximation is inspired by the ML heat equations which are discussed in Section REF .
